The MicroDAQ SRL-120A is a general purpose digital I/O products which communicate to the host PC via an RS-232 or RS-485 (dependent on model) serial connection. Based on the industry standard 82C55 PPI device. It features 120 TTL level digital I/O lines. The I/O can be programmed in banks of 8 as inputs or outputs.

Two interface versions are available for the serial MicroDAQ range, these include RS-232 models and RS-485 models. The RS-232 models are best suited for short distances (up to 30 meters).

The RS-485 models allow for long distance data transmission (up to 1200 meters). These RS-485 models are ideally suited for process control applications in a plant or industrial environment, which require long cable runs.

This digital I/O product is ideal for use in the connection between a computer and the outside world. Allowing computer programs not only to sense real world events, but control them as well. Applications include man-machine interfacing, driving high power loads, sensing switch contact closures and much more.